Can mating with a different ethnicity than yourself give your offspring favorable genes?

P1 and P2 would have to have favorable genes for their offspring to inherit them--better genes do not spring up from nowhere. P1 and P2 might (only might) be less likely to carry the same recessive genes that they could both pass on to their offspring (some recessive genes are so widespread that being from a different continent does not reduce the chances of passing on a genetically recessive disease (if both parents have the recessive gene and pass it on)). Mutations can occur at any time so their offspring is not immune to genetic problems.